#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>
#include <unordered_map>
using namespace std;

int longestPalindrome(string s) {
    unordered_map<char, int> hash;
    for (int i = 0; i < s.size(); ++i)
    {
        hash[s[i]]++;
    }

    int ret = 0;
    for (auto& [x, y] : hash)
    {
        ret += y / 2 * 2;
    }


    return ret < s.size() ? ret + 1 : ret;
}

int main()
{

	return 0;
}